Super Best Audio Friends

The evolution of the original irreverent and irrelevant and non-authoritative site for headphone measurements, i.e. frequency response graphs, CSD waterfall plots, subjective gear reviews. Too objective for subjectivists; too subjective for objectivists

I heard about this little USB-C dongle DAC/amp called the Helm Bolt from Michael Lavorgna's website Twittering Machines. He used to write for stereophile and audiostream, I always liked his writing style and alternative taste in music even though I was not always a big fan of the types of products he was pushing.

I hooked up the Bolt to my 2008 Mac Pro using the included USB-A adapter, to my iPhone XR using a USB-C to Lightning adapter, and to my modern Windows desktop PC. sound quality was rather crummy from the motherboard of my desktop PC, excellent on my Mac, and in between the two with the iPhone although leaning much closer towards the quality of the Mac. I mention this as YMMV depending on what you USB source you plug the Bolt into.

Rockna Wavelight - Holo Audio Spring2 KTE listening evaluation Blind ABX testing used to confirm ability to discriminate differences between DACs. The results are shown below


During the first run (training) challenge step 5 was not correctly discriminated. The two successive runs were perfectly discriminated.

At this extraordinary level of performance Wavelight and Spring2 KTE sound more similar than different. Please keep in mind the differences described below are subtle but differentiable as demonstrated in ABX testing above.
Let's take a look at IEMagni measurements. First off, let's do 1kHz steady-state sine waves. This is the one that rules them all and of the SINAD is derived from. Note that the voltages I use are lower than that of another site. I run the output -3dBU which is ~0.550mVrms.


Schiit IEMagni Medium Gain
1kHz Steady-State Sine Wave
-3dbU output into 30-ohms, normalized to 0dbC
The timing of this conversation and the necro of the Leben CS300XS thread is rather very very interesting! It's super funny because I fortuitously happened upon another classic push-pull pentode amp just last night. This one is much better IMO! So instead of Leben, why not a reconditioned Fisher KX-200?


And how much do vintage (real NOS is practically non-existent today) EL84's cost today? Let's keep in mind that for a two-channel PP, we need four of them. I don't know how hard the Leben runs the power tubes, but these things tend to be driven harder in a speaker than DHTs used in headphone amps. That is, they are wear items that will die. Finally, there's no way for Leben to offer vintage tubes because of cost, availability, and reliability. A good percentage of "strong" or "NOS" tubes bought on eBay aren't really so when I put them on the Amplitrex tube tester. I also eschew amps that need spheshal tubes to sound good (mids and highs will be better, but the lows will still be loose). Great amps IMO sound good with current production tubes, but sound better with exotic tubes. FWIW, the KX-200 uses the rather unknown 7591. Unknown is that it isn't a EL84 or EL34. I am beginning to think that the 7591 is darn good sounding tube overlooked by PP amp designers today. I'm using new production JJ 7591 in my KX-200 right now and the amp sounds darn good.
I do not want to buy a pair of bloody HD650’s to have as a general reference. If I did I would want the most neutral version/mod/whatever possible. no thank you

I hate the HD650 except when powered by nuclear reactors and I’ve bought one like 3 times trying to like it. And I think they are way overhyped here on SBAF and would like to prove ortho superiority some day. but i find myself in a situation where a reference would be a good thing and the HD650 seems like a good candidate since it’s kind of the opposite of the skewed sense of neutral I have wound up with and it’s used everywhere and there’s tons of measurements.

I’m thinking a KISS modded pair or other mod that has been measured by @purr1n with no extra tweaks from the measured version. One which is neutral not bright at all. and I don’t like electrodynamics in general hence the dark side. I currently only own one electrodynamic driver and that’s in my Solaris og iem.

First off, I’d thank Evans and ETA friends for adding me to the loaner tour of ESX900 (along with Genesis brothers as well). Was extremely excited about this opportunity largely because (1) I heard too many good things for Evan’s works since he messed with HFM but couldn’t have any chance so far (shame on me...); and (2) I am now planning to prepare post-covid life – more specifically, I must pick up a very serious closed-back pair for myself to alleviate hard work and tough schedules at work.


Before moving forward, I want to make it hyper clear that no matter how harshly I will go, this is one awesome pair I have ever experienced. Good things were already well documented elsewhere, and to make my post as concise as possible, I took out all the shameless love-lettering statements, which could alter tone of this post greatly. Anything I don’t describe in this post would be no less than good/decent.
I picked these two DACs because they seemed comparable in price and implementation, with the Soncoz SGD1 using one of the latest ESS parts ES038Q2M (x2) and the JNOG using a single 4493EQ. Both offer balanced outputs and designed with measurements in mind.

First of all, the Soncoz DAC is a usability disaster. The JNOG by contrast was x500 simpler to use. Plug in stuff into JNOG. Press power button. Press input button to cycle inputs until I hear sound. The Soncoz SGD1 I found extremely frustrating to the point where I wanted to throw it out onto the street and run it over with my Jeep. There's some part of me that still wants to do that and film it to put in on YouTube. Words cannot express the level of frustration I had with this Soncoz DAC. Basically, there are no buttons on the front. There is a large knob that can be rotated and pushed in like a button - and that's it - well except for a remote control which is just as confusing. All functions arise from this knob, input selection, filter selection, volume, mute. Who knows.


Proceeds will go to charity. Auction: Schiit Magni 3+ Headphone Amplifier Signed by Jason Stoddard, the man himself. This will likely be a rare piece of gear going forward.


The scratches on the top plate are evident in the photo. This unit was assembled at the new Schiit factory in Corpus Christi by Schiit workers. It is not an aftermarket deal where parts were cobbled together like the guy who sold the 666 Satan Nike shoes. The only difference is that a black volume knob is used to denote this special one of a kind piece of gear signed by Mr. Stoddard.
Haven't seen anyone post about these headphones yet as they are mostly local to Russia but starting get more recognized internationally and deserved more recognition among music lovers and audiophiles. Official website:

NM-1 (Flagship)

These headphones are the result of years of research in acoustics, accuracy and fidelity of the musical signal. Their design is based on a meanderless isodynamic transducers which significantly reduces losses and distortions from mutual crosstalk in closely spaced conductors with opposite current direction (which is typical for all traditional isodynamic and orthodynamic headphones)
If you have to ask... I was curious. Got this to compare against Modius and see if it can replace Modius in a less expensive rig. TL;DR: I don't think I'm hearing the SGD1 as like a "superior" take over Schiit Modius. It's more "different" if anything. SGD1 is brighter, with slightly more grain in the treble region, and less bass impact. Modius is warmer, darker, with markedly smoother (but still kinda grainy?) treble and more bass impact.


So in conclusion, I think the SGD1 is... okay. It's probably not the most offensive D-S DAC I have heard, but it's also not... amazing either. I was hoping it would spank Modius handily in most areas, considering the price point and how much some folks have been raving about it. But I don't think that's the case here. In fact, Modius still has better bass than SGD1 by a large margin: more impact, more body, more texture, more bass details, while everything else (mid and treble and soundstage) are just kind of "different" on SGD1 without being "better". On some songs, I can tell SGD1 may be preferable to Modius with HD650, but I'd much rather have Modius in the chain with HD800, even if I'm using a tube amp.
To my gf’s kindness, I could evaluate the newly released HE400SE ‘Global Edition’[1] this quickly. Sharing hands-on impressions and measurements.

[1] HFM claims the global edition to be different from the original domestic ones released last winter. As per HFM, the primary difference is whether to use “stealth magnets”. Perhaps a rip-off version of Audeze’s Fazor I suspect. For convenience, I will call this HE400SE global edition simply “HE400SE” as domestic versions only sold in the China mainland.

Unlike HFM’s lower end models so far, they actually don’t sound shitty. The tonality falls down to somewhere in between Arya/HE1000 and modded HE6s. Maybe closer to the former. Much smoother in mids and highs. Plastic timbre and scooped upper midrange still there but each slightly improved. Overall, the most enjoyable 400-series HFM ever released.


Oh, I forgot telling this. This pair of headphones sold (effectively[2]) $120 new. What happened to Fang Bian lol?
Very briefly, these are bassy IEMs. With respect to the Atlas and Vega, from memory, the Vega 2020 don't seem to be as bass cannon-ish. If the Vega 2020 are slightly V-shaped with a slight roll-off at the top, then the Atlas are more U-shaped with some sizzle at the top. The OG Vega seemed to exhibit some sibilants which receded to some extent after a certain number of hours of use. The Vega 2020's mid treble and air regions are smooth, slightly muted even. With neutral desktop amps, there's a bit of brittleness in the highs. With warmer sources, e.g. Sony ZX2, xDuoo, Shanling M6, this brittleness goes away.

Silicon tips yielded a bit less bass with some lift toward the lower treble lift. Foam tips were bassier with flatter upper mids and muted highs. I didn't try deep insertion because the flanges are narrower than usual and I was afraid of losing a looser fitting tip in my ear.

Campfire Audio Vega 2020 vs 64 Ears U18t (WHT)
Frequency Response